Firecallie,
You and I are in virtually the same situation. My mom is dead set (literally) on drinking herself into the grave. I have given up on expecting her to change, there is absolutely nothing I can do to stop her and since she has her faculties I cannot get her committed.
I really don't have any advice for you that you probably have not already heard before i.e. counseling or al-anon. Please take care of yourself, get enough rest, eat right, exercise and pray or meditate.
There are so many people here who have walked this road abd can give you good advice on how to cope with your pain. You might also check out the spirituality section under friends and family.
Which I had more to offer, please come back often and let us know how you are doing.